摘要
针对一台实际的并联机床,简化过约束结构,在运动学方程一次微分和二次微分的基础上,进行相关性分析,整合相关性强的辨识参数,推导出z向垂直度误差近似唯一相关于立柱倾斜系数,从输出误差测量的角度实现对误差源的分类。同时利用简单可行的相对误差测量方案,基于相关性分析的结论,采用分步标定方案,显著提高精度,大工作空间内达到±0.04 mm以内,局部在±0.02 mm以内,满足了工程需要。该方法基于参数间以及参数和输出误差间的相关性分析,有效简化标定过程,实现参数的分步辨识,为并联机床标定提供了新思路。
The over-restriction of a parallel kinematic machine (PKM) is simplified and through analysis the 1-differential and 2-differential kinematic equation, the identified parameters among which there are strong relationships are eliminated and it proves that the vertical tolerance along z axis is approximately only related with the non-vertical coefficient of the two columns, so that the parameter errors are classified from the view of output errors. Based on the only relationship of the z axis vertical tolerance, calibration of the PKM is carried out by two steps through a simple scheme about relative position measurement. The results show that in almost all workspace the accuracy is improved to below ±0.04 mm and in partial workspace the accuracy to below ±0.02 mm, so that the industrial requirement is satisfied. The method based on relativity analysis can simplify the calibrating process and identify parameters step by step. Then it gives a new way for PKM calibration.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2005年第1期88-92,共5页
Journal of Mechanical Engineering
基金
国家973重点基础研究基金(G1998030607)国家自然科学基金(50305016)资助项目。
关键词
并联机床
相关性
标定
误差补偿
Parallel kinematic machine Relativity Calibration Error compensation
